The hardest part about day trading is the emotional battle, traders told BI about their professions. Those trying to turn a profit in markets said they often struggled with the toll of volatile trading days. They found measures such as seeing a psychologist and journaling to be helpful. Day trading isn't so much a science as it is an emotional test. That's the secret to day trading that outsiders don't seem to understand, retail traders told me at a recent happy hour in New York's Financial Distric ...